When a table of contents note starts with a subfield 't' (which is valid) the XSLT doesn't show it because (i think) it's looking for a subfield 'a' only.
Created attachment 3305 [details] [review] patch
Pushed and merged, please test
This works for me.
This bug is mentioned in: Bug 5816: XSLT doesn't display enhanced contents http://lists.koha-community.org/pipermail/koha-patches/2011-March/014060.html